SMTP协议通信时遇到的问题
[code=C/C++][/code]
char buff[1024]={'\0'};
recv(talkfd, buff, 1024, 0);

send(talkfd, "HELO 163\r\n", sizeof("HELO 163\r\n"), 0);
recv(talkfd, buff, 1024, 0);

send(talkfd, "AUTH LOGIN\r\n", sizeof("AUTH LOGIN\r\n"), 0);
recv(talkfd, buff, 1024, 0); // 这个地方总是返回 500 5.5.1 Invalid command

在dos命令下这个地方执行都是正常的

[解决办法]
何必自己写呢, 有的是开源库.